Comparison of Three Modelling Frameworks for Aquatic Ecosystems: Practical Aspects and Applicability

Abstract Freshwater ecosystems are under multiple stressors and it is crucial to find methods to better describe, manage, and sustain aquatic ecosystems. Ecosystem modelling has become an important tool in integrating trophic relationships into food webs, assessing important nodes using network analysis, and making predictions via simulations. Fortunately, several modelling techniques exist, but the question is which approach is relevant and applicable when? In this study, we compare three modelling frameworks (Ecopath, Loop Analysis in R, STELLA software) using a case study of a small aquatic network (8 nodes). The choice of framework depends on the research question and data availability. We approach this topic from a methodological aspect by describing the data requirements and by comparing the applicability and limitations of each modelling approach. Each modelling framework has its specific focus, but some functionalities and outcomes can be compared. Predictions of Ecopath’s Mixed Trophic Impact plot and the Loop Analysis models are in agreement for groups at higher trophic levels, but not for lower trophic levels. This suggests that further comparisons are needed of networks of varying resolution and size. Generally, when data are limiting, loop analysis can provide qualitative predictions, while the other two methods provide quantitative results, yet rely on more data.